Electrically operated gas vent for fire protection sprinkler systems

ABSTRACT

An automatic electrical gas vent, method and resulting fire protection sprinkler system, is useful with a water source and at least one sprinkler. The at least one sprinkler is connected with the water source by a piping network. An automatic electrical gas vent is adapted to be connected with the piping network to discharge gas from said piping network. The automatic electrical gas vent includes an electrically operated valve that is electrically actuatable to discharge from said piping network and a sensor. The sensor senses the presence of gas at a portion of the piping network and causes actuation of the valve to discharge from the piping network in the absence of a conductive liquid.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit and priority of U.S. Patent Application No. 61/653,733 filed May 31, 2012. The entire disclosure of the above application is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present application is directed to an automatic gas vent assembly and method that is useful in a fire protection sprinkler system and a fire protection sprinkler having such vent assembly. While illustrated for use with an inert gas source, it may be used for the removal of any trapped gas, such as air, from a sprinkler system, such as a wet pipe sprinkler system.

International Patent Application Publication No. WO 2010/030567 A1 entitled FIRE PROTECTION SYSTEMS HAVING REDUCED CORROSION, published on Mar. 18, 2010, the disclosure of which is hereby incorporated herein by reference, discloses use of a gas vent assembly with an inert gas source to fight oxygen corrosion in a fire protection sprinkler system. Previous gas vent assemblies have been entirely mechanical in operation. However, electrical circuits are sometimes used to monitor the status of prior gas vents.

SUMMARY OF THE INVENTION

The present patent application is directed to an electrically operated automatic gas vent assembly and method used for removal of gas in a fire protection sprinkler system. The technique disclosed herein may be used with an inert gas source for inerting the piping network of, or for the removal of, trapped air in a wet pipe sprinkler system.

An aspect of the present invention is directed to a gas vent and method that may be used with a fire protection sprinkler system including a water source and at least one sprinkler. The at least one sprinkler is connected with the water source by a piping network. The automatic gas vent is adapted to be connected with the piping network to discharge gas from said piping network. The automatic gas vent includes an electrically operated valve that is electrically actuatable to discharge from said piping network and a sensor. The sensor senses the presence of liquid at a portion of the piping network and causes actuation of the valve to discharge gas from the piping network in the absence of liquid.

The sensor may cause withholding of actuation of the valve in the presence of a liquid. The electrically operated valve may be closed in the absence of electrical actuation. In this manner, the automatic gas vent will be closed upon the loss of electrical power. A pressure-operated valve may be provided in air communication with the automatic gas vent. In this manner, the automatic gas vent discharges gas only above a particular pressure across the pressure-operated valve. The pressure-operated valve may be a pressure relief valve, a check valve, or the like. Operation of the pressure-operated valve may emit an audible indicator, or the like, when the automatic gas vent is discharging gas from the piping network.

A redundant gas vent may be provided to vent gas and retain liquid upon non-operation of the automatic electrically operated gas vent. The redundant gas vent may be a mechanical gas vent, such as one in the form of a float-operated valve.

An electrical control may be provided that is responsive to the sensor and to electrically actuate the automatic electrically operated valve to discharge in response to the sensor sensing the presence of gas, but not electrically actuate the electrically operated valve in response to the sensor sensing the presence of liquid.

The automatic electrically operated valve may be configured to not discharge if the electrical control does not receive electrical power. The control may include at least one indicator that is adapted to provide an indication of whether the valve is being electrically actuated. The indicator may include a first indicator to indicate that said valve is closed and a second indicator to indicate that the valve is opened.

An inert gas source may be connected with the piping network. The inert gas source may be a nitrogen generator, or other inert gas source.

These and other objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an electrically operated gas vent assembly, according to an embodiment of the invention; and

FIG. 2 is an electrical schematic diagram of a control useful with the gas vent assembly in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings and the illustrative embodiments depicted therein, a fire protection sprinkler system 10 includes a water source 11, such as a source of city water, or the like, one or more sprinklers 13, such as fusible sprinkler heads that are actuatable by heat, or the like, and a piping network shown at 12 that interconnects water source 11 with sprinkler heads 13 (FIG. 1). In order to combat oxygen corrosion, a source of inert gas 14, such as a nitrogen generator, nitrogen bottles, or the like, are connected with piping network 12 in order to displace oxygen with inert gas. System 10 may generally be of the type disclosed in U.S. Patent Application Publication No. WO 2010/030567 A1 entitled FIRE PROTECTION SYSTEMS HAVING REDUCED CORROSION, published on Mar. 18, 2010, and U.S. Patent Application Publication No. WO 2011/162988 A2, entitled HIGH NITROGEN AND OTHER INERT GAS ANTI-CORROSION PROTECTION IN WET PIPE FIRE PROTECTION SYSTEM, published on Dec. 29, 2011, the disclosures of which are hereby incorporated herein by reference.

In order to displace gas, such as oxygen, from the interior of piping network 12 or from the water in piping network 12, an automatic gas vent assembly 16 is connected with piping network 12 to discharge gas from said piping network. In contrast with conventional mechanical gas vents, automatic gas vent assembly 16 is electrically operated. Automatic gas vent assembly 16 is made up of an electrically operated valve, such as a solenoid-operated valve 18 that is electrically actuatable to discharge from piping network 12 and a sensor 20. Sensor 20, which is an electrical conductance probe, is configured to infer the presence of gas at a portion of piping network 12 (low conductance) or liquid, namely, water, at that portion of the piping network (high conductance) and to cause actuation of valve 18 in response to low conductance to discharge from piping network 12 in the presence of gas. Conversely, sensor 20 causes valve 18 to not be actuated in the presence of a liquid, namely, water or other conductive liquid, in response to the increase in electrical conductance caused by the probe coming into contact with the conductive liquid. This configuration results in an automatic vent that vents gas, but not liquid, from the portion of piping network 12 where gas vent assembly 16 is connected.

In the illustrated embodiment, automatic electrically operated valve 18 is a normally closed solenoid-operated valve that is configured to close in the absence of electrical actuation. In this fashion, valve 18 will be closed should gas vent assembly 16 loose electrical power. While the loss of power will prevent vent assembly 16 from performing its venting function, the loss of electrical power will not allow water or other substance to be discharged through vent assembly 16. In the illustrated embodiment, vent assembly 16 includes a pressure-operated valve 22, such as a pressure relief valve 24 in air communication with automatic electrically operated valve 18. Pressure relief valve 24 causes vent assembly 16 to discharge gas only above a particular pressure across said pressure-operated valve 22. In the illustrated embodiment, pressure relief valve 24 is set to a nominal value of 40 pounds per square inch gauge (PSIG), but other values may be set either with factory settings or manually in the field. The function performed by pressure relief valve 24 is to create a 40 PSIG gas bubble inside of pipe network 12. This prevents venting at pressures below 40 PSIG, which may be beneficial during nitrogen inerting of wet pipe fire protection sprinkler systems as disclosed in U.S. Patent Application Publication No. WO 2011/162988 A2, entitled HIGH NITROGEN AND OTHER INERT GAS ANTI-CORROSION PROTECTION IN WET PIPE FIRE PROTECTION SYSTEM, published on Dec. 29, 2011, the disclosure of which is hereby incorporated herein by reference. This function could, alternatively, be provided by a ball check valve that allows venting of the piping network, but does not allow oxygen rich air to enter the piping network during drainage of the piping network. Moreover, the presence of a 40 PSIG air bubble inside of pipe network 12 will create an expansive decompression of gas during drainage of piping network 12. This clears the pipes in the piping network thus removing water from around sensor 20. This 40 PSIG bubble holds much more gas volume than an atmospheric bubble and is more effective in clearing sensor 20 of water during the drainage operation. Also, pressure relief valve 24 prevents the ingress of high oxygen content air during draining of piping network 12.

Automatic gas vent assembly 16 may optionally include a redundant gas vent module 26 that is adapted to vent gas and retain liquid upon non-operation of automatic gas vent 16. Redundant gas vent 26, in the illustrated embodiment, is made up of a mechanical gas vent. In the illustrated embodiment, gas vent 26 is a float-operated valve of the type made by Apco. Redundant gas vent 26 prevents any water leakage from piping network 12 should sensor 20 or electrically operated valve 18 fail.

Automatic gas vent assembly 16 includes an electrical control 28 that receives an input from sensor 20 and produces an output to actuate electrically operated valve 18 (FIG. 2). While shown as operated from 110 volts alternating current (AC), other voltages and current type may be used. Electrical control 28 is responsive to sensor 20 to electrically actuate electrically operated valve 18 to discharge from pipe network 12 in response to sensor 20 sensing a low electrical conductance from the presence of gas. Likewise, electrical control 28 does not electrically actuate electrically operated valve 18 in response to sensor 20 by electrical cable 31 sensing a high electrical conductance from the presence of liquid. Electrical control 28 includes a probe control 30 that is connected with sensor 20 and operates a relay 34 depending upon the conductance of sensor 20. Relay 34, in turn, actuates the solenoid of electrically operated valve 18, which is illustrated as a normally-closed solenoid actuated valve through electrical cable 33. Control 28 has visual indicators that provide an indication of whether said valve is being electrically actuated. The visual indicator may be a “red” indicator 36 to indicate that valve 18 is open and/or second “green” indicator 38 to indicate that the valve is closed.

While the foregoing description describes several embodiments of the present invention, it will be understood by those skilled in the art that variations and modifications to these embodiments may be made without departing from the spirit and scope of the invention, as defined in the claims below. The present invention encompasses all combinations of various embodiments or aspects of the invention described herein. It is understood that any and all embodiments of the present invention may be taken in conjunction with any other embodiment to describe additional embodiments of the present invention. Furthermore, any elements of an embodiment may be combined with any and all other elements of any of the embodiments to describe additional embodiments. 

1. A fire protection sprinkler system, comprising: a water source and at least one sprinkler, said at least one sprinkler being connected with said water source by a piping network; and an automatic a gas vent that is connected with said piping network and adapted to discharge gas from said piping network, wherein said automatic gas vent comprises an electrically operated valve that is electrically actuatable to discharge from said piping network and a sensor, said sensor comprising a liquid sensor that is adapted to sense the presence of liquid at a portion of said piping network and to cause actuation of said valve to discharge from said piping network in the absence of liquid.
 2. The system as claimed in claim 1 wherein said sensor is adapted to cause withholding of actuation of said valve in the presence of a liquid.
 3. The system as claimed in claim 1 wherein said electrically operated valve is adapted to close in the absence of electrical actuation.
 4. The system as claimed in claim 1 including a pressure-operated valve in air communication with said vent, wherein said vent discharges gas only above a particular pressure across said pressure-operated valve.
 5. The system as claimed in claim 4 wherein said pressure-operated valve comprises a pressure relief valve or a check valve.
 6. The system as claimed in claim 4 including an audible indicator that indicates discharge from said pressure-operated valve.
 7. The system as claimed in claim 1 including a redundant gas vent that is adapted to vent gas and retain liquid upon non-operation of said gas vent. 8-9. (canceled)
 10. The system as claimed in claim 1 including an electrical control, said electrical control responsive to said sensor and to electrically actuate said electrically operated valve to discharge as a function of electrical conductivity of said sensor. 11-15. (canceled)
 16. The system as claimed in claim 1 including an inert gas source connectable with said piping network.
 17. The system as claimed in claim 16 wherein said inert gas source comprises a nitrogen generator.
 18. An automatic gas vent assembly that is adapted to be connected with a fire protection sprinkler system piping network that is selectively supplied with water from a water source, said gas vent being adapted to discharge gas from said piping network, wherein said gas vent comprises: an electrically operated valve that is electrically actuatable to discharge and a sensor, said sensor adapted to sense the presence of liquid and to cause actuation of said valve to discharge in the absence of liquid.
 19. The automatic gas vent assembly as claimed in claim 18 wherein said sensor is adapted to cause withholding of actuation of said valve in the presence of a liquid.
 20. The automatic gas vent assembly as claimed in claim 18 wherein said electrically operated valve is adapted to close in the absence of electrical actuation.
 21. The automatic gas vent assembly as claimed in claim 18 including a pressure-operated valve in air communication with said vent, wherein said vent discharges gas only above a particular pressure across said pressure-operated valve. 22-23. (canceled)
 24. The automatic gas vent assembly as claimed in claim 18 including a redundant gas vent that is adapted to vent gas and retain liquid upon non-operation of said gas vent. 25-26. (canceled)
 27. The automatic gas vent assembly as claimed in claim 18 including an electrical control, said electrical control responsive to said sensor and to electrically actuate said electrically operated valve to discharge in response to said sensor sensing the presence of gas.
 28. The automatic gas vent assembly as claimed in claim 27 wherein said electrical control does not electrically actuate said electrically operated valve in response to said sensor sensing the presence of liquid.
 29. The automatic gas vent assembly as claimed in claim 27 wherein said electrically operated valve is adapted to not discharge if said electrical control does not receive electrical power.
 30. The automatic gas vent assembly as claimed in claim 27 wherein said control includes at least one indicator that is adapted to provide an indication of whether said valve is being electrically actuated. 31-32. (canceled)
 33. A method of substantially avoiding oxygen-based corrosion in a fire protection sprinkler system having a water source and at least one sprinkler, said at least one suspect connected with said water source by a piping network and a gas vent connected with said piping network to selectively discharge gas and not water from said piping network, said method comprising: wherein said gas vent comprises an automatic gas vent assembly having an electrically operated valve that is electrically actuatable to discharge from said piping network and a sensor, said sensor adapted to sense the presence of liquid at a portion of said piping network; causing actuation of said valve to discharge from said piping network when said sensor does not sense the presence of liquid; and withholding actuation of said valve to not discharge from said piping network when said sensor senses the presence of liquid. 